Solar Terrestrial Activity Report [Image] Last update December 11, 2000 at 04:40 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update December 2, 2000) - Has cycle 23 peaked?] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update December 2, 2000)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update December 2, 2000)] [Historical solar and geomagnetic data charts 1954-2000 (last update October 20, 2000)] Recent development The geomagnetic field was quiet to unsettled on December 10. Solar wind speed ranged between 571 and 716 km/sec under the influence of a high speed coronal stream. Solar flare activity was low. Solar flux was 146.6, the planetary A index was 9 (3-hour K indices: 3323 2322, Boulder K indices: 3223 2222). Region 9254 decayed quickly and was quiet. [SEC/NOAA has, incredibly, listed region 9254 as spotless!] Region 9257 decayed into spotless plage. Region 9258 reemerged with a couple of spots [Listed as spotless by SEC/NOAA.]. Region 9260 was quiet and stable and has rotated over the west limb. Region 9262 was mostly quiet and stable, as was region 9263. New region 9264 rotated into view at the southeast limb. New region 9265 rotated partly into view at the northeast limb. Flares and CMEs A total of 2 C class events were recorded on December 10. Region 9262 produced a C3.3 flare at 95:05 UTC, the flare may have been associated with a filament eruption stretching from the north of the region until the east limb. A large filament eruption was observed at high latitudes in the northeast quadrant, most of the activity occurred at the same time as a C2.8 event was recorded (peak time at 19:35 UTC). Although both filament eruptions produced CMEs it does not currently appear likely that the CMEs were geoeffective. The background x-ray flux is at the class B4 level. Coronal holes A small coronal hole in the northern hemisphere will rotate into a possibly geoeffective position on December 12 or 13. Forecast The geomagnetic field is expected to be quiet to unsettled on December 11-13. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is poor. Coronal holes (1) Coronal mass M and X class flares (3) ejections (2) [Coronal hole indicator][CME indicator] [M and X class flare indicator] 1) Effects from a coronal hole could reach earth within the next 5 days. 2) Material from a CME is likely to impact earth within 96 hours. 3) There is a possibility of either M or X class flares within the next 48 hours. Green: 0-20% probability, Yellow: 20-60% probability, Red: 60-100% probability. Active solar regions (Recent map) Solar Date Actual no. Location at region numbered sunspots midnight Area Classification Comment 9249 20001130 N09W87 plage 9253 20001203 S14W80 plage 9254 20001203 5 (estimated) N10W32 0030 CAO 9255 20001203 N23W25 plage 9256 20001204 S17W15 plage 9257 20001206 N19W16 plage 9258 20001207 2 (estimated) N14E09 0000 BXO 9259 20001207 S09W61 plage 9260 20001207 1 S04W91 0000 AXX 9262 20001208 4 N13E43 0080 DAO 9263 20001209 1 N18E51 0000 AXX 9264 20001210 1 S21E65 0060 HSX 9265 20001210 1 N19E70 0030 HSX Total number of sunspots: 15 (estim.) Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 1999.11 191.5 133.2 111.0 (+3.2) 1999.12 169.8 84.6 111.1 (+0.1) 2000.01 158.1 90.1 112.9 (+1.8) 2000.02 174.1 112.9 116.7 (+3.8) 2000.03 208.2 138.5 119.9 (+3.2) 120.8 (+0.9) 2000.04 184.2 125.5 cycle 23 peak candidate 2000.05 184.9 121.6 119.0 (-1.8) 2000.06 179.8 124.9 (118.3 predicted, -0.7) 2000.07 202.3 169.1 (119.8 predicted, +1.5) 2000.08 163.0 130.5 (120.5 predicted, +0.7) 2000.09 182.1 109.9 (119.6 predicted, -0.9) 2000.10 167.4 100.1 (118.4 predicted, -1.2) 2000.11 178.8 106.5 (116.4 predicted, -2.0) 2000.12 151.8 (1) 36.5 (2) 1) Running average based on the daily 20:00 UTC solar flux value at 2800 MHz. 2) Unofficial, accumulated value. The official value is typically 25-40% less. This report has been prepared by Jan Alvestad. It is based partly on my own observations and interpretations, and partly on data from sources noted in solar links. Comments and suggestions are always welcome. ------------------------------------------------------------------------ [DX-Listeners' Club] [DX News] [StudyWeb]